NAG Library Manual, Mark 28.4
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NAG CL Interface Introduction
Example description
/* nag_specfun_erfcx_real (s15agc) Example Program.
 *
 * Copyright 2022 Numerical Algorithms Group.
 *
 * Mark 28.4, 2022.
 */
/* Pre-processor includes */
#include <nag.h>
#include <stdio.h>
int main(void) {
  /*Integer scalar and array declarations */
  Integer exit_status = 0;
  /*Double scalar and array declarations */
  double x, y;

  NagError fail;
  const char *str_fail;

  INIT_FAIL(fail);

  printf("nag_specfun_erfcx_real (s15agc) Example Program Results\n");
  /* Skip heading in data file */
  scanf("%*[^\n] ");
  printf("\n%s\n\n", "       x          erfcx(x)     fail");
  while (scanf("%lf%*[^\n] ", &x) != EOF)
  {
    /*
     * nag_specfun_erfcx_real (s15agc)
     * Scaled complement of error function, erfcx(x)
     */
    y = nag_specfun_erfcx_real(x, &fail);
    if (fail.code != NE_NOERROR) {
      if (fail.code == NW_HI || fail.code == NW_NEG || fail.code == NW_REAL) {
        /* nag_code_to_error_name (x04ndc).
         * Converts NAG error code to its string value
         */
        str_fail = nag_code_to_error_name(fail.code);
        printf("%14.5e  %-14.5e %s\n", x, y, str_fail);
      } else {
        printf("Error from nag_specfun_erfcx_real (s15agc).\n%s\n",
               fail.message);
        exit_status = 1;
        goto END;
      }
    } else {
      printf("%14.5e  %-14.5e\n", x, y);
    }
  }

END:

  return exit_status;
}